The present invention is directed to a carton transfer unit. More particularly, the present invention is directed to a carton or package transfer unit for use with a form, fill and seal packaging machine that receives partially erected cartons at one pitch, orientation and spacing, moves the cartons through a reorientation and respacing step for application of a process on the cartons and orients and spaces the cartons for further processing.
Consumers have come to recognize and appreciate resealable closures for containers to store, for example, liquid food products and the like. These resealable closures permit ready access to the product while providing the ability to reseal the container to prolong the life and freshness of the product and to prevent spills after initial opening of the container. Typically, the containers or cartons are formed from a composite of paperboard material having one or more polymer coatings or layers to establish a liquid impervious structure.
In known containers having such closures, the closures, which are formed in a separate process and transported to the packaging process, are conventionally affixed to the containers as part of the overall form, fill and seal operation. Typically, the closures are affixed to the partially erected carton prior to filling the carton with product. One known method for affixing the closure to the carton uses an ultrasonic welding process. In this process, the carton is partially erected and the closure is brought into contact with the carton, overlying an opening in the carton. Subsequently, an anvil is placed against the carton material and an ultrasonic horn is brought into contact with a flange of the closure. The ultrasonic horn is actuated which ultrasonically welds the flange to the carton material.
Another method for affixing closures to cartons uses an induction heating process. In this process, again, an anvil is placed on the carton material and an induction sealing head is brought into contact with the flange. A current is induced in the induction sealing head which, again, results in welding the flange to the carton.
Still another method applying closures to cartons is to directly mold the closure on the carton. Such a method is, for example, disclosed in Lees, et al., U.S. Pat. Nos. 6,467,238 and 6,536,187, which patents are commonly assigned with the present application and are incorporated herein by reference. The apparatus and method in the patents to Lees et al., include inserting a carton into a mold station, closing the mold tools on the carton, injecting a polymer into the mold cavity to form the closure, opening the mold tool and removing the carton (with the closure molded thereon) from the mold apparatus.
It has been found that direct molding the closures onto the cartons (as compared to applying/affixing the closures to the cartons) has a number of advantages. First, there is no longer a need for the equipment to store, transport and apply the closures to the cartons. Although the direct molding methods require equipment for carrying out the molding, there is less equipment needed for direct closure molding application. Moreover, and quite importantly, there is no longer a need for closure supply. Eliminating the reliance on the supply of closures is important for a number of reasons. First, there is always the possibility that the supply of closures is interrupted. This, of course, impacts the entire form, fill and seal operation in that operations must cease until closures are available for the cartons.
In addition, in that machine operations may vary based upon product demand, it is desirable to not have to maintain a large quantity of closures on hand (to, for example, satisfy high demand). Moreover, it is easier to maintain a quantity of “raw” polymer or plastic on hand to meet demand. In that the polymer is typically supplied and stored in pellet form, it requires less space and is more readily commercially available than preformed closures.
Nevertheless, there are many form, fill and seal machines presently in use that continue to use conventional closures. Moreover, many parts of these machine use a number of known, “standard” carton pitches and orientations. For example, machines are manufactured for filling cartons having standard 70 mm by 70 mm and 95 mm by 95 mm cross-sections. The cartons, however, are fed onto mandrels in the form, fill and seal machine in different pitches and orientations. Regardless, in order to reduce the costs for providing such direct molded closures, it is desirable to maintain one standardized orientation and format for such a molding apparatus.
Accordingly, there is a need for an apparatus that permits use of a standardized molding apparatus with various different form, fill and seal packaging machines. The resulting “common” parts provides considerable economic advantage. Desirably, such an apparatus can be “inserted” into any of a number of standard form, fill and seal machines with minimal changes required to the machine. Most desirably, such an apparatus is used without adversely impacting the overall form, fill and seal machine operation.